Transformations of Consciousness
I think that you make a good point when speaking of people who have different perceptions being, or viewed as unwell mentally. Obviously, there are those who really do have psychotic ideas and those who are just creative Bohemian. There is a whole spectrum, and many who speak of their peak experiences may be labelled as unwell, even though they are not. I am sure that many of the most creative people of all times, if they had lived in our times may have been detained in hospital and medicated against their will. They may not have created their greatest work at all.
I find that even beyond talking about peak experiences, a lot of people think that philosophy is peculiar. The people who live in the same house as me seem a bit puzzled about how I spend so much time reading and writing. As far as I can see they seem to spend most of the time on practical tasks. I am inclined to be completely minimalist over practical tasks, such as cooking. I probably get my room so untidy because I am spend so little time tidying. I also can't bear sport, playing or watching it. I think most people see me as an arty misfit.
One other matter, is the whole idea of outsider art, and that is about different perceptions, and of art created by people who have not been trained in art school. There is also the perspective of being on the edge in alternative music subcultures, ranging from goth, emo, punk and rap. I do think that music is often an expression of peak states of consciousness. I don't create music, but I do find that listening to it is a way of accessing certain states of consciousness. This may also connect to the shamanic quest. I definitely see John Lennon, whose lyrics you quoted, as well as so many of the great rock stars as being shamanic figures.